Acquisitions (Details) - USD ($) $ in Thousands	Dec. 31, 2025	May 31, 2022
Business Combinations [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt and finance lease liability	$ (7,900)	$ (46,800)

Business Combination Long-term Debt, Smith Transport

No definition available.

Name:	htld_BusinessCombinationLongTermDebtSmithTransport
Namespace Prefix:	htld_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant